by Kelly Kennedy, USA TODAY

by Kelly Kennedy, USA TODAY

WASHINGTON - Routine costs, not requirements of the Affordable Care Act, contributed to the majority of health insurance rate increases in the last year, a new study released Thursday shows.

"It wasn't driven by utilization of the services, but the unit costs," said Mike McCue, lead author of the study by The Commonwealth Fund, a nonprofit group devoted to improving health services for Americans. "That will continue to be a major driver moving forward - trying to control those medical expenses - if they want to remain profitable."

The report also found that just 1 percentage point of insurers' increases was due to the first fully implemented changes from the Affordable Care Act: women's preventive care and contraceptive services, which began in August 2012.

"Women's costs were in full effect for the study," McCue said. "But the insurers saw that as one little portion, looking at the narrative."

The researchers analyzed the narratives the law requires each insurer to file when they raise their rates by more than 10% in plans created after March 23, 2010. They investigated rate increases of 10% or more from July 2012 to June 2013 for policies that cover at least 150 people.

McCue is a health administration professor at Virginia Commonwealth University and co-author Mark Hall is a law and public health professor at Wake Forest University.

They found that increased medical costs - more expensive medications, procedures and exams - accounted for the entire amount of the rate increases in the individual market. Insurers, however, also reduced their overhead for administrative expenses by $25 a year per person insured, the study found.

Health care providers have negotiated higher rates from insurers, which is driving up costs,' McCue said. "Hospitals are gaining greater advantage when they go in to negotiate."

This has led many insurers, spurred by the new law, to move to new payment plans in which providers are paid by the patient rather than by the medical procedure. Insurers have also moved toward requiring generic medications over name-brand drugs and toward smaller provider networks.

Twenty states had no approved rate increases of 10% or more. In others, insurers that sought higher premiums accounted for 1% or less of the total enrollment in that market. Connecticut, Idaho, Maine, Maryland, Ohio, Indiana, Washington and West Virginia were affected the most by increases.

Half of the insurers attributed at least some parts of their increases to the Affordable Care Act, the study showed, more so in the individual market than the small-group market.

"This finding is somewhat surprising, given that the health reform law is expected to have a greater impact on individual insurance," the report said.

Next year could provide more changes, McCue said, as new provisions of the law take effect. That includes a larger insurance market driven by enrollment through federal and state health exchanges and the end of higher premiums for people with pre-existing medical conditions.

"Going forward, they want to be profitable," McCue said of the insurers. "It's very hard to predict the subsequent year because it's a whole new ballgame."